Development of Three-Dimensional Scour below Pipelines in Regular Waves

Journal of Marine Science and Engineering

Liquan Xie¹  Tsung-Chow Su²  Tsunming Wong³  Yehui Zhu⁴ 

[1] College of Civil Engineering, Tongji University, Shanghai 200092, China;Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL 33431, USA;School of Civil Engineering, Tsinghua University, Beijing 100084, China;School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China;

关键词: pipeline scour;    three-dimensional scour;    scour propagation rate;    regular waves;    Keulegan–Carpenter number (KC number);   

DOI  :  10.3390/jmse10020124

来源: DOAJ

【 摘 要 】

The three-dimensional scour beneath a partially-buried pipeline in regular waves was visualized using a miniature camera installed in a transparent pipeline. The scour mechanism was analyzed based on the results. Scour development was observed to start at the upstream edge of the span shoulder when the flow in the span headed downstream. The nearby sediment scoured quickly, and a new scour front formed, which can be attributed to the deflected flow entering the scour hole. The new scour front retreated gradually. The end of the original scour front deformed and moved downstream, probably due to the enhanced seepage flow near the edge of the span shoulder. After that, the new scour front extended to the downstream interface of the sediment and the pipeline, and continued to retreat until the first half of the scour process ended. In the second half of the scour process, the sediment transportation occurred in a similar but mirror-imaged manner. The scour hole propagation rate was also determined based on visualization. The results show that the scour hole propagation rate under a pipeline decreases with an increasing pipeline embedment ratio and rises with the KC (Keulegan–Carpenter) number, which is similar to the result of a previous study.

【 授权许可】

Unknown